The effects of UV light on the polymerization of photoresist / Husna Ahmad Tarmizi

In this study, the p-type and n-type silicon wafer is coated with positive photoresist. Both coating process is using spin on photoresist. The effects of UV light exposure and etching time is studied between thin and thick photoresist thickness on both type of silicon wafer. The photoresist thickness will be fixed using only 2.5ml volume liquid photoresist when the UV exposure time is varied at 5s, 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s and also 50s. The same applies when the photoresist thickness is fixed using only 5.0ml volume liquid photoresist, the same UV exposure time is varied. Other parameters that had been fixed are spin-coat speed and time; at 1000 rpm for 10 seconds in order to get uniform photoresist thickness throughout the wafer surface. After photoresist coating process and UV exposure via Wafer Photoresist Module (WPM) and Aligner and Exposure respectively, the etching time or known as development time will be taken using stop watch. Data of polymerization or known as etching rate versus UV exposure time is plotted into graphs and had been compared between thin and thick photoresist and also different types of silicon wafer.